How to intercept 802.15.4 frames while using Thread

[Jochen0x90h]

Hi!

I read that your Thread stack uses a different 802.15.4 implementation than the MAC driver. Is it possible to intercept special broadcast data packets e.g. from energy harvesting switches while using thread?

The special packets that I want to intercept have a MAC header that looks like this:

Frame Control: 0x0801 (use short addresses)

Sequene Number: 1 byte

Address field: 0xffffffff (short destination address and pan id)

Source address and pan are not included

Is there a possibility to use Thread and set a callback to intercept these packets and process them "by hand" and pass everything else on to Thread?

Thanks,

Jochen

[Jochen0x90h]

It seems to work using otLinkSetPcapCallback() in link.h

[Edvin]

Hello Jochen,

Sorry for the late reply.

Were you able to receive non-network packets using otLinkSetPcapCallback()?

These energy harvesting switches typically do not have enough power to run the radio in RX mode, so they will not be part of the network. Just so you know, this means that if you do an action on these switches, this will be vulnerable to reply attacks. But it would be you who decide whether or not this is an issue. Even if you have some sort of key, the keys in Thread networks are regularly updated to prevent replay attacks. This is just an FYI.

Best regards,

Edvin

[Jochen0x90h]

Yes it seems to work. The switch that I use even has a sequence counter and a checksum generated by some encryption algorithm so replay is not (easily) possible like in car keys. The next question if this still works when thread and zigbee are used simultaneously. otLinkSetPcapCallback() is an openthread function, how do packets get forwarded to the zigbee stack?

[Edvin]

You can't run thread an zigbee simultaneously. I don't think there is a similar function in Zigbee. The Zigbee stack is a closed source stack (developed by an external company), so I don't have access to check how the packets are forwarded to the zigbee stack. Knowing that you can't use Thread and Zigbee simultaneously, is that still a valid question? Whether or not it is possible to receive raw data packet when using the Zigbee Stack?

[Jochen0x90h]

Does the Zigbee stack use the same radio driver like the thread stack? Or is the radio driver part of the closed source Zigbee stack? It would still be interesting if it is possible to receive raw data packets using the Zigbee stack.